US2197524A - Wire drawing furnace - Google Patents

Description

April 16, 1940. J. H. GREEN ET Al.

WIRE DRAWING FURNACE Filed sept. 1o, 1937 wml .ummm

ATTORNEY Patented Apr. 16, 1940 PATENT 'OFFICE DRAWING FURNACE James H. Green, West Orange, and Henry K. Richardson, Bloomfield, N. J'., assignors to Westinghouse Electric & Manufacturing Company, East Pittslurgh, Pa., a corporation of Pennsylvania Application September 10, 1937, 'Serial No. 163,206

10 Claims.

'I'his invention relates to wire drawing, and, more particularly, to an improved furnace for heating refractory metal filaments toa desired temperature prior to passing to the drawing die.

The principal object of our invention, geni erally considered, is to provide a furnace for heating moving wire uniformly to a desired temperature.

Another object of our invention is to provide a furnace having a series of closely-spaced burner elements, so that the temperature therein is substantially uniform. f

A further object of our invention is the provision of a wire drawing furnace comprising a i in place by an annular member threadably secured to the wall defining said port.

Other objects and advantages of the inven. tion, relating to the particular arrangement and construction of the variousv parts, will become apparent as the description proceeds.

Referring to the drawing illustrating our invention:

Fig. 1 is a fragmentary side elevational view, partly in vertical section, of wire drawing apparatus embodying our invention.

Fig. 2 is a transverse sectional view on the line II--II of Fig. 1, in the direction of the arrows.

Fig. 3 is a fragmentary horizontal sectional view on the "line III-III of Fig. l, in the direction of the arrows.

Fig. 4 is, a transverse sectional View on the line IV-IV of Fig. 1, in the direction of the arrows.

Fig. v5 is a perspective view of one of the refractory burner elements or tips.

Referring to the drawing in detail, like parts being designated by like reference characters, there is illustrated a reel l0, rotatably mounted on a standard Il, resting on a suitable support or table l2,v and from which tungsten or other wire i3 is fed to the oven I4 embodying our invention, after passing through a lubricant supply, if desired, such as the aquadag fountain I5. Aquadag is a well known wire-drawing lubricant containing graphite, such as referred to in the Benbow Patent No. 1,168,050. The oven of the present invention is desirably adjustably mounted on standards I6, resting on the support or table I2, as by means of bolts I1 passing through slots i8 in plates I9, secured to and depending from the oven block 20.

'I'he oven proper I4 comprises the block 20 which, in the present embodiment, is formed by taking a bar of cold-rolled steel, rectangular in section, as shownv most clearly in Fig. 4, and elongated to the desired length, as shown most clearly in Fig. 1, and forming therein a gas chamber 2l, offset toward one side as by drilling the bar from end to end and closing the ends of the apertured portion by screw plugs 22, as shown most clearly in Fig. 3. Combustible gas desirably premixed with the required proportion of air or oxygen, is shown supplied to the chamber 2| by means of a pipe 23, in communication with a central portion thereof, as illustratedin Fig. 1, but may, and in most instances preferably is, supplied through two or more inlets.

Burner ports 24 are provided in the furnace block 20, as by drilling so as toleave shoulders 25 engaged by the refractory or porcelain burner elements 26, which fit in place in the larger portions of the ports 24, being desirably secured in placeV as by annular lockingelements 21, threadably engaging the walls dening the ports 24 in the block 20. The annular members 21 are desirably-provided with notches 28, forengagement byascrew driver or the like, for tightening them in place.

Each burner element 2 6 is desirablyv formed, as shown in detail in Fig. 5;l that is, generally cylindrical with the bottom face concave or dished, as indicated at 29, notches 30 extending outwardly from said dished portion to allow gas to feed to the annular space 3l between the burner element and the furnace block 20. Each burner element is also provided with a laterally extending iiange 32 notched, as indicated at 3 3, to permit the combustible gas mixture to pass between said ange and the adjacent wall of the block 20. f Each burner element is also formed with a frusta-conical outwardly extending central portion 34, adapted to be heated to in- Y candescence by flame jets issuing from the ports f defined by notches 35 in an outwardly extending through the-length of the furnace, we desirably slots 40 in said straight portion. The outer portion of the reflector 31 is curved upwardly to provide a substantially cylindrical portion 4I, partly surrounding the wire I3 and with its inner surface when used for moderate temperatures, or those below 490 C., desirably polished orformed highly reflecting as by chromium plating, as indicated at 42, so as to. reect heat from the burner elements 26 back to the wire I3.

When used for higher temperatures, it has been found that 'a highly reflecting surface soon tarnishes, so, for uniformity of results, itis prefi erable to start with a dull finish, or one which can be maintained. 'Ihe upper edge of the reflector 31 is desirably spaced from the adjacent face of the block 20, to leave a slot permitting the placement of wire to be treated and the exhaust of waste gases.A

After passing through the furnace I4, the wire I3 -goes tothe drawing die 42, mounted like the furnace on a standard 43, desirably supported on the same table I2. On account of the adjustable mounting of furnace I4, the distance between the adjacent end thereof and said die may be varied as desired. y

After passing through the die 42, Athe wire I3 is wound up on a suitable reel 44, which may lbe power driven as by means of a belt 45 from a.

motor, not shown. If desired, the wire may pass between guide rolls 46 and 41 on its way to the winding reel.

From the foregoing, it have devised an improved apparatus for wire drawing including a furnace in which an elongated series of refractory burner elements are mounted so that heat therein is approximately uniform from end to end. The burner elements,

or flame-producing means, are desirably uni-- formly positioned so close together that the ames issuing therefrom overlap or merge, giving the eect of a continuously uniform heat zone from one en`d burner to the other.` Although the number of burner elements or tips is not the essence of the invention, yet we have found that a satisfactory design of furnace desirably comprises more than ten, and we have used as many as forty burner elements. It will, however, be understood that the number may be varied within the desired limits, dependingon the speed, size, and density of the filament, and the ternperature of the die, the main idea being that all of the moisture in the aquadag, or other lubribrought to the desired uniform temperature be- `fore it 'passes to the die.

From a consideration of the foregoing, it will be seen that we have provided for heating the wire in three ways:- first, by heat energy radiated directly from the refractory burner elements and flames issuing therefrom; second, by conducted heat; and, third, by reected heat.

Although a preferred embodiment of the invention has been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

We claim:

1. A furnace comprising a block with a gas supply chamber extending approximately the full length thereof, a`plurality of ports extending will be seen that we spaced therefrom.

laterally from a side of said chamber, a gas burner element in each port, and means removably holding said elements in place and cooperating therewith to form flame-jet ports.

2,. A furnace comprising a block with a gas supply chamber extending approximately the full length' thereof, a plurality of ports extending laterally from said chamber, a refractory gas burner element in each port and provided with notches in their outer surfaces, and annularv members threadably secured to said block, replaceably holding said burner 'elements in place, and closing said notchesto form gas-carrying ports providing flame jets outward of said burner elements.

3. A furnace comprising a block with a gas supply chamber extending approximately the full length thereof, a plurality of ports extending laterally from said' chamber, a gas burner element in each port, means holding said elements in place, and a reflector member extending approximately the full length of said block, secured to one face thereof, and curved upwardly and over the side from which the ports extend.

4. A furnace comprising an elongated metal block formed With a chamber extending the full length thereof and offset toward one side, plugs closing the ends of 'said chamber, a gas supply pipe communicating with the central portion of said chamber, ports extending laterally from one side of said chamber, a 'gas burner element in each port, and means replaceably holding said elements in place, said means cooperating with said burner elements to form -ports from which flames issue. l

5. A furnace comprising an elongated metal block formed with a chamber extending the full length thereof and offset toward one side, plugsv closing the ends of said chamber, a gas supply pipe communicating with the central portion of said chamber, ports extending laterally from said chamber, a refractory gas burner element in each port, and an annular member fitting each port outward of the burner element and threadably secured to said block, cooperating with said elements to form flame-jet ports, and holding said elements in place.

6. A furnace comprising an elongated metal block formed with a chamber extending the full length thereof and offset toward one side, plugs closing the ends of said chamber, a gas supply pipe ucommunicating with the central portion of .said chamber, ports extending laterally from said chamber, a gas burner element in each port, means holding said elements in place, and a reflector member extending approximately the full length of said block, secured to one face thereof, and curved upwardly and over the side from which the ports extend.

7. A furnace comprising a gas chamber, more than tenv closely spaced burner elements disposed in line along a side of said chamber and shielded by a concave reflector extending from below and leaving a slit above said elements, said slit extending the full length of said reflector.

8. A furnace comprising a gas chamber, and series of closely spaced llame-producing means disposed along a side thereof and shielded by a concave reflector, the lower edge of which is secured to said chamber and the upper edge 9. A furnace comprising means producing a plurality of laterally directed flames so closely spaced that they overlap, and a cylindrically concave reflector shielding said flames to provide an elongated heat zone of substantially uniform P temperature, the upper edge of said reflector being spaced from said furnace -to provide a slit for the passage of a wire to be treated.

10. A furnace comprising an elongated metal block formedl with a passage extending the full length thereof and o ffset toward one side, plugs closing the ends of said passage, a gas supply pipe communicating with a portion of said passage intermediate said plugs, ports extending laterally from a side of said'passage, a gas burner element in each port, annular members threadably secured to said block and engaging peripheral portions of said elements for holding them in place, said ports being disposed so close together that when the furnace is in use the names therefrom overlap to provide an elongated heat zone of substantially uniform temperature, and a reflector element comprising a' generally flat plate adjustably secured to the lower face of said block, the free portion of said plate being curved cylindrically up and toward a side of said block, to shield the burner elements and provide an elongated chamber, open at its ends and top along a slot between its free upper edge and the adjacent side ofsaid block, for receiving a wire undergoing heat treatment.

JAMES H. GREEN.

HENRY K. RICHARDSON.

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